Method and apparatus for a capacitor shell including two mateable cupped components

ABSTRACT

One embodiment of the present subject matter includes a capacitor, comprising a first cupped shell having a first opening, and a second cupped shell having a second opening, wherein the first opening and the second opening are adapted to sealably mate to form a closed shell defining a volume therein. In the embodiment, the closed shell is adapted for retaining electrolyte. A plurality of capacitor layers in a substantially flat arrangement are disposed within the volume, along with electrolyte, in the present embodiment. The present closed shell includes one or more ports for electrical connections.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is related to the following commonly assignedU.S. patents which are incorporated by reference in their entirety:“High-Energy Capacitors for Implantable Defibrillators,” U.S. Pat. No.6,556,863, filed Oct. 2, 1998, issued Apr. 29, 2003; “Flat Capacitor foran Implantable Medical Device,” U.S. Pat. No. 6,699,265, filed Nov. 3,2000, issued Mar. 2, 2004. Additionally, the present application isrelated to the following Provisional U.S. Patent Application which isassigned to the same assignee and is incorporated by reference in itsentirety: “Method and Apparatus for Single High Voltage AluminumCapacitor Design,” Ser. No. 60/588,905, filed on Jul. 16, 2004.Additionally, the present application is related to the followingcommonly assigned copending U.S. patent application which isincorporated by reference in its entirety: “Heat Shrinkable Wrap forCapacitor,” Ser. No. ______, filed on ______ (Attorney Docket No.279.829US1).

TECHNICAL FIELD

This disclosure relates generally to capacitors, and more particularly,to a method and apparatus for a capacitor shell including two mateablecupped components.

BACKGROUND

There is an ever-increasing interest in making electronic devicesphysically smaller. Consequently, electrical components become morecompact as technologies are improved. However, such advances intechnology also bring about additional problems. One such probleminvolves packaging components in devices.

Packaging is especially problematic with components incorporatingmultiple layers. One such component is the capacitor. Capacitors provideimproved charge storage and energy density using multiple conductivelayers and advanced dielectrics. As the layers become more complex andsmaller in dimensions, problems arise with packaging. Housings forcomplex shapes defining contoured layer stacks are needed.

Thus, there is a need in the art for housing designs which are adaptedto new capacitor stack shapes, and which improve packaging efficiencywithout sacrificing substantial performance of the component.

SUMMARY

The above-mentioned problems and others not expressly discussed hereinare addressed by the present subject matter and will be understood byreading and studying this specification.

In one embodiment, the present subject matter includes a capacitor,comprising: a first cupped shell having a first opening; a second cuppedshell having a second opening, wherein the first opening and the secondopening are adapted to sealably mate to form a closed shell defining avolume therein, the closed shell adapted to retain electrolyte; aplurality of substantially planar capacitor layers in a stackedarrangement disposed within the volume; and electrolyte disposed withinthe volume, wherein the closed shell includes one or more ports forelectrical connections.

In one additional embodiment, the present subject matter includes acapacitor, comprising: a plurality of substantially planar capacitorlayers in a stacked arrangement; a first shell means for partiallyhousing the plurality of substantially planar capacitor layers; a secondshell means sealably mated to the first shell means at a joint anddefining a closed shell means and further defining a volume therein, theclosed shell means for housing the plurality of substantially planarcapacitor layers and for retaining electrolyte; and electrolyte disposedwithin the volume, wherein the plurality of substantially planarcapacitor layers are disposed within the volume and the closed shellmeans includes one or more ports for electrical connections.

One additional embodiment of the present subject matter includes amethod, comprising: positioning a plurality of substantially planarcapacitor layers in a stacked arrangement in a first cupped shell havinga first opening; sealably mating a second opening of a second cuppedshell to the first opening of the first cupped shell along a joint, themated first and second cupped shells defining a closed shell having avolume and at least one electrical port providing access to the volume;and disposing electrolyte in the volume.

This Summary is an overview of some of the teachings of the presentapplication and not intended to be an exclusive or exhaustive treatmentof the present subject matter. Further details about the present subjectmatter are found in the detailed description and appended claims. Otheraspects will be apparent to persons skilled in the art upon reading andunderstanding the following detailed description and viewing thedrawings that form a part thereof, each of which are not to be taken ina limiting sense. The scope of the present invention is defined by theappended claims and their legal equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a capacitor with two cupped shells,according to one embodiment of the present subject matter.

FIG. 2 is a top view of a capacitor case component, according to oneembodiment of the present subject matter.

FIG. 3 is a front view of a capacitor case component, according to oneembodiment of the present subject matter.

FIG. 4 is a side view of a capacitor case component, according to oneembodiment of the present subject matter.

FIG. 5 is a side view of a capacitor case component, according to oneembodiment of the present subject matter.

FIG. 6 is a front view of a capacitor case component, according to oneembodiment of the present subject matter.

FIG. 7 is a cross section of a capacitor case component taken at line“7” in FIG. 5, according to one embodiment of the present subjectmatter.

FIG. 8 is a cross section of a capacitor case component taken at line“8” in FIG. 6, according to one embodiment of the present subjectmatter.

FIG. 9 is a cross section of a capacitor with two cupped shells,according to one embodiment of the present subject matter.

FIG. 10 is a cross section of a capacitor with two cupped shells,according to one embodiment of the present subject matter.

FIG. 11 is an example of a device having a capacitor of the presentsubject matter.

DETAILED DESCRIPTION

The following detailed description of the present invention refers tosubject matter in the accompanying drawings which show, by way ofillustration, specific aspects and embodiments in which the presentsubject matter may be practiced. These embodiments are described insufficient detail to enable those skilled in the art to practice thepresent subject matter. References to “an”, “one”, or “various”embodiments in this disclosure are not necessarily to the sameembodiment, and such references may contemplate more than oneembodiment. The following detailed description is, therefore, not to betaken in a limiting sense, and the scope is defined only by the appendedclaims, along with the full scope of legal equivalents to which suchclaims are entitled.

In various embodiments, flat capacitors with stacked planar orsubstantially planar electrodes are used to power electronic devices.For example, flat capacitors are used in implantable medical devicessuch as implantable cardioverter defibrillators. Capacitors includeanodes and cathodes, and in various embodiments, the anodes and cathodesare divided into interconnected layers.

In part, the nature of implantation and patient comfort requiresergonomically shaped devices for implantation. Ergonomic devices oftenhave curved profiles. In the past, capacitors which are flat haveconsisted of rectangular structures. In creating ergonomic devicehousings which incorporate capacitors with rectangular shapes, space hasbeen wasted, as is the case when a sphere is used to encapsulate a box.

In capacitor embodiments which are not rectangular, but have a curvedprofile, a different problem exists. Capacitor housings have beenefficiently made using a deep-draw process to make a receiving cup,combined with a planar lid mateable to the cup opening. A capacitor witha curved profile can be placed in a deep drawn receiving cup with acurved bottom, using the space around the curved bottom reasonably well.Unfortunately, the deep drawn process is suited to create curves in onlyone direction. For example, forming a cup involves pushing a die againsta plate. The die must then be removed from the plate. Such processes arenot suited to create a unitary sphere shaped piece.

In order to enable capacitors with ovoid or sphere-shaped curves, thepresent subject matter includes, but is not limited to, embodiments witha shell comprised of two mateable cupped components. For example, afirst cup shaped shell can be deep drawn. This example shell can conformto a curved component to be placed in it. The example also includes asecond cup shaped shell, which also is deep drawn. This example secondshell can conform to curved portions of a capacitor shape which aresticking out of the first shell. In this example, a capacitor stack withan ergonomic shape can be efficiently packaged using a two piece casingor shell. This benefit, as well as other benefits, is facilitated by thepresent subject matter.

FIG. 1 shows a flat capacitor 100 constructed according to oneembodiment of the present subject matter. Although capacitor 100 is aD-shaped capacitor, in additional embodiments the capacitor is anotherdesirable shape, including, but not limited to, rectangular, circular,oval or other symmetrical or asymmetrical shapes. Capacitor 100 includesa case 101 which contains a capacitor stack 102. In some embodiments,case 101 is manufactured from a conductive material, such as aluminum.In additional embodiments, the case 101 is manufactured using anonconductive material, such as a ceramic or a plastic. The capacitorstack 102, in various embodiments, is constructed from planar anode,cathode, and separator subcomponents, as is discussed herein.

In various embodiments, the case 101 is divided into a first shell 172and a second shell 174. In some embodiments, the first shell 172 and thesecond shell 174 are cup shaped and/or concave. First shell 172 andsecond shell 174 are mateable to one another, in various embodiments. Insome embodiments, a seam or joint 176 is defined by the matedintersection of the first shell 172 and the second shell 174. Seam 176,in these embodiments, includes various types of known joints, includingbutt joints, step joints, and lap joints. The scope of joints in thepresent subject matter includes joints which are flush to the exteriorbefore welding, joints which are flush to the exterior after welding,joints which are flush to the interior before welding, and joints whichare flush to the interior after welding. In various embodiments, thesejoints start in a non-flush state and are made flush during welding,either by removing metal, or by adding filler metal. In some of theseembodiments, joints which are flush in a beginning state are similarlyadapted to become non-flush after welding.

Capacitor 100 includes a first terminal 103 and a second terminal 104for connecting capacitor stack 102 to an outside electrical component,such as heart monitor circuitry, including defibrillator, cardioverter,and pacemaker circuitry. In one embodiment, terminal 103 includes afeedthrough terminal 140 insulated from case 101, while terminal 104 isdirectly connected to case 101. In additional embodiments, one, two,three or more feedthroughs are used. Terminal 103 comprises an aperturein one or more shells of the case, in various embodiments. Additionally,terminal 103 includes a seal in various embodiments. One embodiment offeedthrough 140 includes epoxy. The capacitor incorporates additionalconnection structures and methods in further embodiments. The presentsubject matter includes, but is not limited to, additional connectionstructures and methods illustrated on pages 12-13, 59-60, 63-82 ofrelated and commonly assigned Provisional U.S. Patent Application,“Method and Apparatus for Single High Voltage Aluminum CapacitorDesign,” Ser. No. 60/588,905, filed on Jul. 16, 2004, incorporatedherein by reference.

Capacitor stack 102 includes one or more cathodes, one or moreseparators, and one or more anodes. Additionally, in some embodiments,these components are organized into capacitor elements 105 a, 105 b, 105c, . . . , 105 n, illustrated through break line 166. A capacitorelement includes at least one anode layer, and at least one cathodelayer. In various embodiments, multiple elements are interconnected. Forexample, in one embodiment a first element having a first anode layer isinterconnected with a second element having a second anode layer, withthe first anode layer and the second anode layer interconnected. Invarious embodiments, stack 102 is formed in two steps, including a firststep of stacking capacitor components into two or more elements 105 a,105 b, 105 c, . . . , 105 n, and a second step of stacking elements intoa capacitor stack. Additional embodiments include forming a capacitorstack in a single step, or more steps. The present subject matterincludes, but is not limited to, additional embodiments disclosed onpages 41-50 of related and commonly assigned Provisional PatentApplication “Method and Apparatus for Single High Voltage AluminumCapacitor Design,” Ser. No. 60/588,905, filed on Jul. 16, 2004, which isincorporated herein by reference.

Each cathode of capacitor stack 102, in various embodiments, is ametallic planar structure. Varying examples include a cathode layerconnected to an additional cathode layers using a variety of methods andstructures, including welding. In some embodiments, the cathodes arecoupled to conductive case 101, and terminal 104 is attached to case101, providing a connection between the cathode and outside circuitry.In some embodiments, the cathode is coupled to a feedthrough assembly.In some embodiments, a feedthrough assembly includes a feedthroughconductor extending through a feedthrough hole. Configurations havingmultiple cathode feedthroughs are within the scope of the presentsubject matter.

Capacitor stack 102 additionally includes one or more anodes, in variousembodiments. Anodes can include aluminum, tantalum, hafnium, niobium,titanium, zirconium, and combinations of these metals, in variousembodiments. In one embodiment, at least portions of a major surface ofeach anode is roughened and/or etched to increase its effective surfacearea. This increases the capacitive effect of the anode on a volumetricbasis.

In various embodiments, anode subcomponents are connected to other anodesubcomponents of the capacitor anode, the connected subcomponentscoupled to feedthrough assembly 103 for electrically connecting theanode to circuitry outside the case. In some embodiments, a feedthroughassembly includes a feedthrough conductor extending through afeedthrough hole. Configurations having multiple anode feedthroughs arewithin the scope of the present subject matter. In some embodiments, theanode is connected to the case and the cathode is coupled to one or morefeedthrough assemblies. In various embodiments, both the anode and thecathode are connected to components through on or more feedthroughs.

In addition to cathodes and anodes, various embodiments include aseparator positioned, in part, to insulate capacitor stack components.One or more separators are used to insulate anode subcomponents fromcathode subcomponents, for example. In various embodiments, theseparator includes one or more sheets of kraft paper impregnated with anelectrolyte. Varying forms of electrolyte includes a fluidic compoundadapted for use in a capacitor. Examples with electrolyte include anyelectrolyte for an electrolytic capacitor, such as an ethylene-glycolbase combined with polyphosphates, ammonium pentaborate, and/or anadipic acid solute.

The present subject matter includes, but is not limited to, anodes,cathodes, separators, and additional components disclosed on pages 29-34of related and commonly assigned Provisional U.S. Patent Application:“Method and Apparatus for Single High Voltage Aluminum CapacitorDesign,” Ser. No. 60/588,905, filed on Jul. 16, 2004, incorporatedherein by reference.

Capacitor embodiments within the present subject matter include acapacitor stack adapted to deliver between 7.0 Joules/cubic centimeterand 8.5 Joules/cubic centimeter. Some embodiments are adapted to deliverabout 7.7 Joules/cubic centimeter. In some embodiments, the anode has acapacitance of between approximately 0.70 and 0.85 microfarads persquare centimeter when charged at approximately 550 volts. In variousembodiments, these ranges are available at a voltage of between about410 volts to about 610 volts.

In various embodiments, the stack is disposed in a case, and linked withother components, a state which affects some of these values. Forexample, in one packaged embodiment, including a case and terminals, theenergy density available ranges from about 5.3 Joules per cubiccentimeter of capacitor stack volume to about 6.3 Joules per cubiccentimeter of capacitor stack volume. Some embodiments are adapted todeliver about 5.8 Joules. In various embodiments, these ranges areavailable at a voltage of between about 410 volts to about 610 volts.

It should be noted that throughout the present application, matchingnumbers indicate similar features and/or functions. Matching numbershelp to explain the subject matter, but the arbitrary nature of shapes,such as capacitor electrode shapes, is emphasized, and matching numbersare not to be interpreted as limiting.

FIG. 2 is a top view of a capacitor case component, according to oneembodiment of the present subject matter. First shell 172 includes arounded portion 202. In various embodiments, a rounded portion such asrounded portion 202 extends to and defines a planar portion 204. Therounded portion 202 is useful for packaging in an ergonomic devicehousing. For example, in various embodiments, a capacitor comprised offirst shell 172 is disposed in a device housing which has an ergonomicexterior. Some embodiments with an ergonomic exterior include asimilarly shaped interior. The shape of first shell 172, includingrounded portion 202, is adapted to mate to such an interior, in variousembodiments.

First shell 172, in various embodiments, is cup shaped. Some cup shapedembodiments are formed using a deep draw process, as is known in theart. Deep drawing processes press a sheet of metal into a shape. Theresulting shape includes first opening 206. Because one or more diesused during this process must be extracted, the shape of the first shell172 is limited, in various embodiments. In deep draw embodiments whichhave dies extracted as such, along axis 208 for example, features offirst shell 172 must not extend orthogonally further away from axis 208than does material defining opening 206.

FIG. 3 is a front view of a capacitor case component, according to oneembodiment of the present subject matter. Visible in the illustration isrounded portion 202 of first shell 172.

FIG. 4 is a side view of a capacitor case component, according to oneembodiment of the present subject matter. In various embodiments, firstshell 172 includes openings 402, 404. First opening 402, in variousembodiments, is useful as an electrical port, such as a feedthrough, oras fill-port. A fill-port is used for filling a capacitor case withelectrolyte, in various embodiments. Various additional uses includingan aperture in first shell 172 are also within the scope of the presentsubject matter. Similarly, opening 404 is useful for a number offunctions. In some of these embodiments, the openings 402, 404 include astep. A step is useful, in various embodiments, for reducing damaginglaser refraction in embodiments which seal a plug to the openings usinglaser welding.

Opening 402 may be drilled, punched, or otherwise formed as is known inthe art. In various embodiments, opening 402 is flush to the interiorand exterior of first shell 172. In additional embodiments, opening 402is not flush. Various embodiments include a bevel, or are otherwiseadapted to provide functions known in the art. One embodiment extendsinto the volume defined by first shell 172 and second shell 174.

FIG. 5 is a side view of a capacitor case component, according to oneembodiment of the present subject matter. In various embodiments, secondshell 174 includes an opening 502. The design of second shell 174 caninclude features, such as rounded edges 506, to comply with ergonomicrequirements, in various embodiments. Opening 502, in one embodiment, isadapted for use as a feedthrough. Some feedthrough designs, includingembodiments of 502, include a wall which extends into the volume definedby first shell 172 and second shell 174. One embodiments of this designis described in portions of this application discussing FIG. 7.

It should be noted that the rectangular shape visible in the side-viewof the second shell 174 should not be understood as limiting. Althoughthe rectangular shape is adapted for housing a rectangular capacitorstack, comprised of layers of capacitor electrodes with similar edgeprofiles, other embodiments are within the scope of the present subjectmatter, including embodiments in which the second shell 174 has ahemispherical profile, a partially ovoid profile, or other profiles.Generally, these embodiments extend away from opening 504 with crosssections, viewed parallel to opening 504, of same or decreasing area.This is due, in various embodiments, to the limitations of deep drawingprocesses, as discussed elsewhere in this application. These embodimentsadd opening 502 after the first die is removed from insertion throughopening 504.

FIG. 6 is a front view of a capacitor case component, according to oneembodiment of the present subject matter. The ergonomic shape of secondshell 174 is visible. Various ergonomic designs include curves ofvarying profiles, including a short radius curve 506, and a long radiuscurve 602. Some curves are compound, comprising two or more radiuses.Wall portion 604 is a planar major surface, in various embodiments. Inembodiments where second shell is purely curvilinear, such as ovoidembodiments, wall portion 604 does not exist.

FIG. 7 is a cross section of a capacitor case component taken at line“7” in FIG. 5, according to one embodiment of the present subjectmatter. Second shell 174 includes opening 502, in various embodiments.Opening 502 can serve as an electrical port, in various embodiments. Theopening 502 is comprised of a wall which extends inward, to the volumepartially defined by the interior wall 704 of second shell 174. As such,the opening is comprised of a face 702.

The shape of opening 502 can be the result of various manufacturingprocesses, as are known in the art. Punching, pressing, and otherwiseforming second shell 174 can result in an opening 502, in variousembodiments. One design feature present in various embodiments is face702. Face 702, in various embodiments, protrudes into the interiordefined by the capacitor shells 172, 174. A simple opening in the shellswould result in a face which is approximately as thick as the shell.Face 702 extends into the shell farther than a simple opening. As such,embodiments using adhesive in a feedthrough benefit from the increasedsize of face 702. The increased size of face 702 improves bonding byenabling more adhesive to contact a surface, in various embodiments.

FIG. 8 is a cross section of a capacitor case component taken at line“8” in FIG. 6, according to one embodiment of the present subjectmatter. The illustration presents one example profile of a shell. Wall802 extends toward an edge, such as an edge used for mating second shell174 to a mateable edge of first shell 172. Wall 604 comprises a majorsurface of embodiments of second shell 174 which have a rectangularcross section.

FIG. 9 is a cross section of a capacitor with two cupped shells,according to one embodiment of the present subject matter. The capacitorcomponents illustrated include a capacitor stack 902, a first shell 972,and a second shell 974. Although the capacitor components comprise anovoid cross section, other embodiments are within the scope of thepresent subject matter, including those with a rectangular crosssection, or those with cross sections shaped otherwise. It is importantto note that the present subject matter is not limited to symmetricalembodiments: asymmetrical embodiments are also within the scope of thepresent subject matter, and can be used to match specially shapeddevices.

Various embodiments include a backing element 978. A backing element978, in various embodiments, is used as a structural element of thecapacitor. For example, if a backing element 978 is attached to oneshell, it can be used in the alignment of a second shell. In embodimentsin which the backing element 978 is welded to one of the first shell orthe second shell, various configurations are possible. Some embodimentsweld the backing element 978 to one shell, creating a step. Someembodiments create a weld which is flush with the exterior of the firstshell 972 and the second shell 974. Additional embodiments create a weldwhich is not flush with the exterior of first shell 972 and second shell974. Additional configurations not enumerated here are also within thescope of the present subject matter.

Backing element 978 is useful in joining processes for capacitorcomponents, in various embodiments. For example, a backing element 978can help reduce harmful effects of laser welding in embodiments usinglaser welding to seal joint 976, for example. Lasers used to connectshells 972, 974 along joint 976 can refract in various embodiments, anddamage other capacitor components. A backing element 978 can reduceinstances of refraction, reducing incidents of damage occurring duringlaser welding. Although backing element 978 is shown with a rectangularcross section, other embodiments are within the scope of the presentsubject matter. Additionally, while space 950 is present in theillustrated embodiment, it does not exist in other configurations.Combinations of capacitor stacks and shell shapes are adapted toeliminate spaces existing between a capacitor stack and a shell, invarious embodiments.

In various embodiments, backing element 978 is attached to orincorporated with a capacitor stack. Some of these embodiments includeincorporating backing element 978 into a covering for capacitor stack902. For example, one of these embodiments includes a backing element978 which is covered and constrained by a film form-fitted to thecapacitor stack. Another example utilizes a form fitting film which hasproperties adapted to reduce damaging refraction. The present subjectmatter additional includes, but is not limited to, embodiments describedin the following related commonly assigned copending U.S. patentapplication, incorporated herein by reference in its entirety: “HeatShrinkable Wrap for Capacitor,” Ser. No. ______ (Attorney Docket No.279.829US1).

FIG. 10 is a cross section of a capacitor with two cupped shells,according to one embodiment of the present subject matter. The capacitorcomponents illustrated include a capacitor stack 1002, a first shell1072, and a second shell 1074. While space 1050 is present in theillustrated embodiment, it does not exist in other configurations, asthey can include components sized to eliminate space 1050. Although thecapacitor components comprise an ovoid cross section, other embodimentsare within the scope of the present subject matter, including those witha rectangular cross section, or those with a cross section shapedotherwise. It is important to note that the present subject matter isnot limited to symmetrical embodiments: asymmetrical embodiments arealso within the scope of the present subject matter, and can be used tobetter match some patient anatomy.

Various embodiments including an interconnect 1080. An interconnect1080, in various embodiments, is used to conduct electricity from thecapacitor stack 1002 to components external to the capacitor. In someembodiments, an interconnect extends from the capacitor stack 1002 toone or more housing components, including shells 1072, 1074. Inembodiments where one or more housing components are conductive, theinterconnect 1080 connects the conductive housing component with thecapacitor stack 1002. These embodiments include anodic case capacitorsand cathodic case capacitors. Connecting the interconnect 1080 as suchis accomplished using a laser weld, in some embodiments. However,connections between interconnect 1080 and capacitor subcomponentsinclude additional embodiments, including additional welding embodimentssuch as sold-state welding embodiments.

In some embodiments, the interconnect 1080 extends to a joint 1076.Joint 1076 is defined by the intersection of housing componentsincluding shells 1072, 1074.

In some of these embodiments, the interconnect is ribbon shaped, andextends from capacitor stack 1002 to joint 1076 and outside of thecapacitor. Some of these embodiments further trim the interconnect sothat it is flush with the exterior of the capacitor housing.Interconnecting the anode or the cathode of capacitor stack 1002 tocomponents external to the capacitor using embodiments havinginterconnect 1080 can reduce manufacturing complexity, and improvemanufacturing efficiency.

Exemplary Embodiment of Implantable Defibrillator

FIG. 11 shows one of the many applications for capacitors incorporatingone or more teachings of the present subject matter: an implantableheart monitor or apparatus 1100. As used herein, implantable heartmonitor includes any implantable device for providing therapeuticstimulus to a heart muscle. Thus, for example, the term includespacemakers, defibrillators, cardioverters, congestive heart failuredevices, and combinations and permutations thereof.

Heart monitor 1100 includes a lead system 1103, which after implantationelectrically contact strategic portions of a patient's heart. Shownschematically are portions of monitor 1100 including a monitoringcircuit 1102 for monitoring heart activity through one or more of theleads of lead system 1103, and a therapy circuit 1101 for deliveringelectrical energy through one or more of the leads to a heart. Monitor1100 also includes an energy storage component, which includes a battery1104 and incorporates at least one capacitor 1105 having one or more ofthe features of the exemplary capacitors described above.

In addition to implantable heart monitor and other cardiac rhythmmanagement devices, one or more teachings of the present subject mattercan be incorporated into cylindrical capacitors and/or capacitors usedfor photographic flash equipment. Indeed, teachings of the subjectmatter are pertinent to any application where high-energy, high-voltage,or space-efficient capacitors are desirable. Moreover, one or moreteachings are applicable to batteries.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement which is calculated to achieve the same purpose maybe substituted for the specific embodiment shown. This application isintended to cover adaptations or variations of the present subjectmatter. It is to be understood that the above description is intended tobe illustrative, and not restrictive. Combinations of the aboveembodiments, and various embodiments, will be apparent to those of skillin the art upon reviewing the above description. The scope of thepresent subject matter should be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled.

1. A capacitor, comprising: a first cupped shell having a first opening; a second cupped shell having a second opening, wherein the first opening and the second opening are adapted to sealably mate to form a closed shell defining a volume therein, the closed shell adapted to retain electrolyte; a plurality of substantially planar capacitor layers in a stacked arrangement disposed within the volume; and electrolyte disposed within the volume, wherein the closed shell includes one or more ports for electrical connections.
 2. The capacitor of claim 1, wherein the first cupped shell has a different profile than the second cupped shell.
 3. The capacitor of claim 1, wherein the intersection between the first cupped shell and the second cupped shell is a lap joint.
 4. The capacitor of claim 1, wherein the intersection between the first cupped shell and the second cupped shell is a butt joint.
 5. The capacitor of claim 1, wherein the first cupped shell has at least one electrical port.
 6. The capacitor of claim 5, wherein a joint defined by the intersection of the first opening and the second opening includes an electrical port.
 7. The capacitor of claim 1, further comprising: a backing element disposed between an intersection between the first cupped shell and the second cupped shell and the plurality of substantially planar capacitor layers.
 8. The capacitor of claim 7, wherein the backing element is integrated with a binding film conformed to the plurality of substantially planar capacitor layers.
 9. The capacitor of claim 1, further comprising: a first major surface of the first cupped shell, and a first wall extending between the first major surface and the first opening; and a second major surface of the second cupped shell, and a second wall extending between the second major surface and the second opening, wherein the first major surface and the second major surface are substantially parallel.
 10. The capacitor of claim 9, wherein an edge surface defined by the first wall and the second wall is substantially continuous.
 11. The capacitor of claim 10, wherein the first wall and the second wall define a substantially planar surface.
 12. The capacitor of claim 10, wherein the edge surface is curvilinear.
 13. A capacitor, comprising: a plurality of substantially planar capacitor layers in a stacked arrangement; a first shell means for partially housing the plurality of substantially planar capacitor layers; a second shell means sealably mated to the first shell means at a joint and defining a closed shell means and further defining a volume therein, the closed shell means for housing the plurality of substantially planar capacitor layers and for retaining electrolyte; and electrolyte disposed within the volume, wherein the plurality of substantially planar capacitor layers are disposed within the volume and the closed shell means includes one or more ports for electrical connections.
 14. The capacitor of claim 13, wherein the first shell means has a different profile than the second shell.
 15. The capacitor of claim 13, wherein an edge surface proximal the joint is substantially continuous.
 16. A method, comprising: positioning a plurality of substantially planar capacitor layers in a stacked arrangement in a first cupped shell having a first opening; sealably mating a second opening of a second cupped shell to the first opening of the first cupped shell along a joint, the mated first and second cupped shells defining a closed shell having a volume and at least one electrical port providing access to the volume; and disposing electrolyte in the volume.
 17. The method of claim 16, further comprising a substantially continuous edge surface proximal the first joint.
 18. The method of claim 16, further comprising positioning a backing element between the joint and the plurality of substantially planar capacitor layers.
 19. The method of claim 18, wherein the backing element is integrated with a film binding the capacitor stack.
 20. The method of claim 16, further comprising welding the first cupped shell to the second cupped shell.
 21. The method of claim 20, further comprising laser welding the first cupped shell to the second cupped shell. 